Page 104 - The Cell in 40 Topics

ifferent hormones give rise to their own particular effects
on the cells comprising the relevant organs. For example,
the messages carried by the insulin and glucagons—which
regulate the level of sugar in the bloodstream—have exactly opposite struc-
tures. For that reason, each hormone sets in motion different communica-
tions channels inside the cell. Receptors working like a communications
switchboard locate the communication molecules, to which they will for-
ward reports without fail (Figures 83 and 84).
At this phase, any wrong choice will damage the communication net-
work and give rise to serious diseases that could even prove fatal. Yet the
literally expert behavior of the receptors in the cell membrane maintains
perfect communication.
This leads us to some important questions: How do the receptors
stimulated by different hormones select, without error, the messenger pro-
teins they need to combine with? How do these receptors manage to fulfill
their duties without ever causing fatal errors?
Recent scientific research has helped us find the answers to these

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